川东北地区三叠系飞仙关组高硫化氢气藏成因探讨

川东北地区三叠系飞仙关组是一套重要的区域性含气层，部分气藏以硫化氢含量高为突出特征。该区高硫化氢气藏主要形成于硫酸盐-碳酸盐沉积组合中，气藏的分布与沉积相带密切相关，主要分布于台地边缘暴露浅滩的沉积环境中。研究表明，高温还原作用是其主要成因机制，水解作用是其次要成因机制。

Discussion on the forming cause of gas reservoir contained high H2S in Feixianguan formation of Triassic in the northeast of Sichuan

Feixianguan formation of Triassic in the northeast of Sichuan region was a suit of important regional gas - bearing beds. Partial gas reservoir was distinctly characterized as high content of H2S. The gas reservoir with high H2S mostly formed in carbonate - sulphate sedimentary combination in this area. The distribution of the gas reservoir was closely related to sedimentaryfacies belt,which was mostly distributed in exposed shoal sedimentary environment at the edge of mesa. High temperature deoxidization was the primary forming mechanism, and hydro-lytic action was the secondary forming mechanism.